Homeostasis, the balance and stability of the human organism, has been the central theme of self-contemplation since prehistory. This concept of a life-preserving equalization process appeared in the writings of ancient Greeks, who conceived of four humors in order to provide a working hypothesis for understanding the internal environment of the human body. Each of us is composed of trillions and trillions of cells, supervised by the neocortex, coordinated through intercommunication by chemical and electromagnetic phenomena, which vitalize the microcosm of the body. Because I enjoyed reading this book while on a 2-month camping trip in Alaska, I came to realize how homeostasis parallels the finely tuned balance of nature in a wilderness environment, a similar, but external, macrocosm.